Circuit-breaker.



F. W. HARRIS.

CIRCUIT BREAKER.

APPLICATION FILED JAN. 10, 1908.

Patented Jan. 19, 1915.

- UNITED STATES PATENT OFFICE.

FORD W. HARRIS. OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO WESTINGHOUSE ELECTRIC 6c MANUFACTURING COMPANY, OF EAST PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.-

CIRCUIT-BREAKER.

Specification of Letters Patent.

Patented Jan. 19, 1915.

Application filed January 10, 1908. Serial No. 410.2473

1 '0 all whom it may concern:

Be it known that 1, FORD \V. HARRIs, a citizen of the United States, and a resident of W'ilkinsburg. in the county of Allegheny and State of Pennsylvania, have invented a new and useful. Improvement in Circuit- Breakers, of which the following is a specification.

My invention relates to automatic circuit interrupters and it has for its object to provide an improved device of the class above indicated that shall be simple and durable in construction and effective in operation.

My improved circuit breaker embodies means for compensating for the wearing away of the engaging contact members, is compact in construction, comprises a relatively small number ofparts and may be easily operated by hand.

Figure 1 of the accompanying drawings is a side elevation of a circuit interrupter constructed in accordance with my invention and in an intermediate closed position, parts being broken away. Fig. 2 is a side elevation, in open position, of the interrupter shown in Fig. 1. Fig. 3 is a sectional view on the line IIIIII of Fig. 1, with the shunt broken away and the main sprin removed.

Referring to the drawings, the device here illustrated comprises an insulating plate or slab 1, a stationary contact member 2, a movable contact-bearing member 3, an operating handle lever 4. a tripping mechanism 5 and a release magnet The movable contact-bearing member 3 comprises a punched or stamped sheet metal arm 7 pivotally mounted on a stationary pin 8, said pin being supported from the plate 1 by means of an U-shaped bracket 9. A laminated contact member 10 is secured to the free end of the arm 7 and an auxiliary contact member 11. is resiliently connected to the arm by means of a spring 12. The side pieces of the inner end of the arm 7, which is of U-shape in cross-section. are provided with slots 13 through which the extremities of the pin 8 project, a lostniotion connection between the arm and the stationary U-shaped bracket 9 being thus provided.

The stationary contact member 2 co1nprises a block 1 1, a terminal bolt 15 and an O nated contact member 10.

auxiliary contact-bearing projection 17, the block 14L having a beveled contact surface 16 to be engaged by the free end of the lami- A contact member 18, which is adapted to cooperate with the contact member 11, is secured to the projection 17. The bolt 15 serves as one terminal of the circuit-breaker and is provided with a plurality of nuts 19 in order that a. line conductor may be readily connected to the interrupter on the back of the plate or slab 1. The opposite terminal of the interrupter consists of a bolt 20 similarly provided with nuts 21 and extending through the plate 1 and through the base of the U-shaped bracket 9. and electrically connected to the lower extremity of the arm 7 by means of a flexible shunt 21. The head of the bolt 20 serves to support one end of a spring 22 which is interposed between the plate or slab and the contact-bearing arm 7 and is secured to the latter by means of a projec tion 28.

The inner extremity of the handle lever 4: is bifurcated and is pivotally mounted on a pin 25 which is supported in the parallel side portions of the arm T. A lost-motion connection is established between a stationary pin 26, which extends through the U- shaped bracket 9. and the handle lever by means of links 27, the inner ends of which are pivotally mounted on the outer extremitics of the pin 26 and the outer ends of which are slotted to receive the ends of a pin 28 which extends laterally through the handle lever 4 at a point intermediate its ends, this slot and pin connection being provided in order that the members 3, a and 27 which -are connected together. and all of which diate position during the closing operation of the device.

The tripping mechanism 5 comprises a tripping lever which is fulcrumcd upon the pin shaft and is located between the legs of the handle lever -l. The tripping lever is provided with three arms one of which constitutes a latch 29 which is adapted to engage a square rod or pin 30 when the interrupter is closed. A second arm 31 of the tripping leverxis provided with a spring 32 which separates it from the -.rin 7 and tends to rotate the latch into engagement with the square rod 30. The third arm 33 extends outwardly and downwardly from the shaft'25 and is actuated by an armature 3t ot' the tripping magnet 6, under predetermined conditions of current or voltage in w the circuit protected by the interrupter, the

circuit connections of the magnet Winding being arranged in accordance with well known practice.

The armature 3% of the tripping magnet 6 is pivotally secured to the outer extremity of a supporting bracket 35 which is secured to and extends from the plate '1 below the magnet winding 6. gap which normally exists between the magnet core 3!) and the armature 34: may be adjusted by means of I a screw 37 which is tapped into the lowerextremity of the armature, this part of the armature being bent nwardly so that the extremity of the adjusting screw engages th' support 35. Other types of tripping mechanism may be easily adapted to the device, such as those in which adjustment is made by keeping the air-gap constantand adding weights or spring tension toincrease the pull.

The operation of the device is as follows: Assuming that the circuit interrupter is open, it may be closed by raising the handle lever 4 to first bring the contact members 11 and 18 into engagement with each other and then to further compress the spring 22 until the latch 29 engages the rod 30"as shown in full lines in Fig. 1, after which the operating handle is allowed to drop to the position indicated in dot and dash lines, by reason-of the slotted ends of links 27. It will be understood that the arm 7 and associated contact members are retained by the latch 29 in their closed position as shown in full lines. Before the latch engages the rod 30, the spring 22 obviously tends to open the circuit interrupter, since it is located between the plate 1 and the arm 7 and on the ame side of the stationary fulcrum 8 as the contact members 10 and 11. After the latch 2 has beenbrought into engagement with the rod 30, the spring 22 tends to force the contact members 10 and 14 and 11 and 18 into engagement with each other by reason of the lost motion connection between the arm 7 and pin 8 and by reason of the, fact that the latch 29 is pivotally secured to the arm 7 between the contact members and the spring support 23. By the arrangement of parts shown, a single spring serves the double purpose of creating a considerable The extent of the airpressure between the contact members when the interrupter is closed and of quickly separating the contact members as soon as the circuit interriptcris released. The circuit interrupter. when closed. may be released,

- either automatically or manually, by a slight movement of the tripping'lever in opposition to the spring 32. which may readily be accomplished through the arm 33.

The contact members do not pertain to my present invention except as they are parts of an operative combination and any well known practice may be followed in their construction and arrangement. It is also to be understood that variations in the size and arrangement of parts of the operating mechanism of the interrupter may be eitected without departing from the spirit of my invention, and T desire that only such limitations shall be imposed as are indicated in the appended claims.

I claim as my invention! 1. In a circuit interrupter,"the combination with stationary and movable contact members, of a 'movable arm having two pivotal points and having the said movable cont-act member operatively connected thereto, and means for rotatin said movable arm about one of the said pivotal points to promote contact pressure between the contact members and for rotating the said arm about the second pivotal point for said movable arm about one of the said pivotal points to promote contact pressure between the contact members and for rotating the said arm about the second pivotal point for separating the same.

In a circuit interrupter, the combination with stationary and movable contact members, a pivotally mounted arm operativcly connectedto said movable contact member, and a latch for holding said contact members inengagement, of a single spring for rotating said movable arm about the said latch to promote contact pressure between the contact members and for rotat ing the said arm about its pivotal point to separate the same when the latch is withdrawn.

4. In a circuit interrupter, the combina 'tion with a stationary insulating support, a contact memberand a bracket fastened thereto, a movable contact-bearing arm connected. thereto, and resilient means for rotating the arm between the latch in engagement with each other, of a spring for pressing the contact members together when the interrupter is closed and for separating the contact members when the holding in arms is released.

5. In a circuit interrupter, the con'ibination with a stationary insulating support, a contact member and a bracket mounted thereon, a movable contact-bearing arm pixotally secured to the said bracket by a lost-motion connection, a contact member secured to the outer end of the arm and a latch secured to an intermediate point in the arm for holding the contact members in engagement with each other, of a spring "for pressing the contact members together when the interrupter is closed and for separating the contact members when the latch is withdrawn, said spring being interposed between the insulating support and the arm and acting upon the said arm between the latch and the lost-motion connection.

6. In a circuit interrupter, the combination with a stationary insulating plate, a bracket on the face of the plate, a contactbearing arm pivotally secured to said bracket by a lost motion connection, a contact member at the outer end of the arm, and a stationary contact member mounted upon the plate, of a latch fulcrun'ied at an intermediate point in the arm and a spring tending to rotate the pivoted end of the arm away from the plate and acting upon and said pivoted end.

T. In a circuit interrupter, the combination with a stationary plate or slab, a bracket thereon, a contact-bearing arm pivotally secured to said bracket, and a cooperating contact member secured to the plate. of a handle lever pivotally connected to an intermediate point in the arm and links pivotally secured, at their inner ends to said bracket and connected by a lost motion connection to the handle at an intermediate point in its length.

In a circuit interrupter, the combination with a stationary plate or slab. a bracket thereon, a contact-bearing arm pivotally secured to said bracket. and a cooperating contact member secured to the plate, of a handle lever pivotally connected to an intermediate point in the arm and links pivotally secured to the bracket between the fulcrum of the arm and the sta tionary contact member and connected to an intermediate point in the handle lever by a lost motion connection.

9. In a circuit interrupter. the combination with a stationary insulating plate or slab. a bracket thereon. a contact-bearing arm pivotally connected to the bracket by a lost motion connection. a contact member secured to the outer end oi the arm. a co operating stationary contact member secured to the plate or slab, and two stationary shafts secured to the bracket between the fulcrum ot' the arm and the stationary contact member. oi a latch pivotally secured to the arm at an intermediate point in its length and adapted to engage one of id stationary shafts, a handle lever also pivotally scoured to the arm at an intermediate point, links interposed between the second stationary shaft and an intermediate point in the handle lever, and a spring interposed between the plate and the arm and acting upon the arm at a point between its t'ulcrum and the latch.

i In a circuit interrupter, the combination with a supporting bracket. a stationary contact terminal. a movable arm having a contact terminal, means for pivotally sup porting said arm at its lower end and a latch t'or' holding said arm in circuit-closing position. of operating means comprising parts respectively connected to the movablc arm and to the supporting bracket at adjacent points and having a lost-motion connection between them.

ll. Tn a circuit interrupter, the combination with stationary and mo able members having cooperating contact terminals, a latch for holding said contact terminals in engagement with eachother, and automatic means for withdrawing'the latch under predetermined conditions, of a single means for rotating the movable member about the said latch for promoting contact pressure between the contact terminals and for rotating the said movable member about its pivotal point to separate them when the latch is withdrawn.

12. In a circuit interrupter, the combination with stationary and movable members having cooperating contact terminals, a latch for holding said contact terminals in engagement with each other. and electromagnetic means for withdrawing the latch under predetermined conditions. of a single means for rotating the movable member about the said latch for promoting contact pressure between the contact terminals and for rotating the said movable member about its pivotal point to separate them when the latch is withdrawn.

13. In a circuit interrupter. the combination with stationary and movable members having cooperating contact terminals, operating means for etlecting the engagement of said contact terminals and means tor restraining said terminals in engagement. said operating means being mechanically linked to said movable member and embodying a lost-motion connection between its parts for permitting said operating means to assume substantiall its open position while the contact terminals are restrained in engagement.

14. In a circuit interrupter. the combination with a stationary contact terminal, a.130

movementofsaid operating handle when 10 said interrupter is closed.

In testimony whereof, I have hereunto subscribed my name this 31st day of Dec.,

FORD \V. HARRIS. Witnesses:

HERBERT FABER, BIRNEY HINES. 

